• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2010년도 정기총회 및 추계학술발표회
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• pp.14-14
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• 2010

Vitamin C (ascorbic acid) is an essential component for collagen biosynthesis and also for the proper functioning of the cardiovascular system in humans. Unlike most of the animals, humans lack the ability to synthesize ascorbic acid on their own due to a mutation in the gene encoding the last enzyme of ascorbate biosynthesis. As a result, vitamin C must be obtained from dietary sources like plants. In this study, we have developed two different kinds of transgenic potato plants (Solanumtuberosum L. cv. Taedong Valley) overexpressing strawberry GalUR and mouse GLoase gene under the control of CaMV 35S promoter with increased ascorbic acid levels. Integration of the these genes in the plant genome was confirmed by PCR and Southern blotting. Ascorbic acid(AsA) levels in transgenic tubers were determined by high-performance liquid chromatography(HPLC). The over-expression of these genes resulted in 2-4 folds increase in AsA intransgenic potato and the levels of AsA were positively correlated with increased geneactivity. The transgenic lines with enhanced vitamin C content showed enhanced tolerance to abiotic stresses induced by methyl viologen(MV), NaCl or mannitol as compared to untransformed control plants. The leaf disc senescence assay showed better tolerance in transgenic lines by retaining higher chlorophyll as compared to the untransformed control plants. Present study demonstrated that the over-expression of these gene enhanced the level of AsA in potato tubers and these transgenics performed better under different abiotic stresses as compared to untransformed control. We have also investigated the mechanism of the abiotic stress tolerance upon enhancing the level of the ascorbate in transgenic potato. The transgenic potato plants overexpressing GalUR gene with enhanced accumulation of ascorbate were investigated to analyze the antioxidants activity of enzymes involved in the ascorbate-glutathione cycle and their tolerance mechanism against different abiotic stresses under invitro conditions. Transformed potato tubers subjected to various abiotic stresses induced by methyl viologen, sodium chloride and zinc chloride showed significant increase in the activities of superoxide dismutase(SOD, EC 1.15.1.1), catalase, enzymes of ascorbate-glutathione cycle enzymes such as ascorbate peroxidase(APX, EC 1.11.1.11), dehydroascorbate reductase(DHAR, EC 1.8.5.1), and glutathione reductase(GR, EC 1.8.1.7) as well as the levels of ascorbate, GSH and proline when compared to the untransformed tubers. The increased enzyme activities correlated with their mRNA transcript accumulation in the stressed transgenic tubers. Pronounced differences in redox status were also observed in stressed transgenic potato tubers that showed more tolerance to abiotic stresses when compared to untransformed tubers. From the present study, it is evident that improved to lerance against abiotic stresses in transgenic tubers is due to the increased activity of enzymes involved in the antioxidant system together with enhanced ascorbate accumulated in transformed tubers when compared to untransformed tubers. At moment we also investigating the role of enhanced reduced glutathione level for the maintenance of the methylglyoxal level as it is evident that methylglyoxal is a potent cytotoxic compound produced under the abiotic stress and the maintenance of the methylglyoxal level is important to survive the plant under stress conditions.

• 한국식품저장유통학회지
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• 제14권3호
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• pp.323-327
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• 2007

본 연구는 PME 처리가 미생물의 생리변화에 미치는 영향을 중심으로 PME의 항균작용을 규명하기 위해서 소수성 분획과 친수성 분획으로 분리하고, 공시균주를 사용하여 미생물의 성장 및 에너지대사 관련효소의 활성에 미치는 영향을 조사하였다. 매실추출물 분획별 항균활성은 변패미 생물인 C. fragariae를 대상으로 paper disk법으로 관찰하였다. 총 추출물(PME)의 소수성 분획은 C. fragariae의 성장을 저해하기는 하나 그 효과가 총 추출물 보다 약한 반면, 친수성 분획은 총 추출물보다 더 뚜렷한 저해 효과를 보였다. 이와 같은 매실추출물의 분획별 미생물의 생육억제효과는 다른 식품부패미생물 군에서도 동일한 패턴을 보여 주었다. B. cereus, E, coli 및 Fusarium sp.에 대해서는 PME의 친수성 분획은 뚜렷한 항균효과를 보여 주었으며, 총 추출물 또한, 항균력을 나타내었으나, 소수성 분획은 낮은 항균력을 보여 본 실험의 공시균주인 C. fragariae에 대한 매실추출물의 분획별 항균효과를 확인할 수 있었다. 매실 추출물첨가 배지 상에서 C. fragariae의 생육이 크게 억제된다는 실험결과를 토대로 매실추출물의 항균활성물질이 미생물 세포내의 효소계의 효소활성을 저해에 기인한 것인가를 알아보기 위하여, 에너지생성대사에 관여하는 몇 가지 효소 활성(glucose-6-phosphate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, hexokinase)에 미치는 매실추출물의 영향을 살펴보았다. 이 결과로 매실추출물은 총 추출물 및 친수성 분획이 일부 에너지 생성대사 효소계의 효소활성에 영향을 미치는 것으로 나타나(12-40%), 매실 추출물의 항균물질이 세포내로 침투되어 membrane에 존재하는 효소의 활성을 억제하는 것으로 추정할 수 있었다. 본 연구결과를 토대로 미루어, 매실추출물의 항균 작용은 세포내 에너지 생성에 관여하는 효소의 활성을 감소시키는 현상에 기인하는 것으로 추정되었다.

• The Korean Journal of Physiology and Pharmacology
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• 제26권4호
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• pp.263-275
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• 2022

There is a paucity of detailed data related to the effect of senescence on the mitochondrial antioxidant capacity and redox state of senescent human cells. Activities of TCA cycle enzymes, respiratory chain complexes, hydrogen peroxide (H₂O₂), superoxide anions (SA), lipid peroxides (LPO), protein carbonyl content (PCC), thioredoxin reductase 2 (TrxR2), superoxide dismutase 2 (SOD2), glutathione peroxidase 1 (GPx1), glutathione reductase (GR), reduced glutathione (GSH), and oxidized glutathione (GSSG), along with levels of nicotinamide cofactors and ATP content were measured in young and senescent human foreskin fibroblasts. Primary and senescent cultures were biochemically identified by monitoring the augmented cellular activities of key glycolytic enzymes including phosphofructokinase, lactate dehydrogenase, and glycogen phosphorylase, and accumulation of H₂O₂, SA, LPO, PCC, and GSSG. Citrate synthase, aconitase, α-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, isocitrate dehydrogenase, and complex I-III, II-III, and IV activities were significantly diminished in P25 and P35 cells compared to P5 cells. This was accompanied by significant accumulation of mitochondrial H₂O₂, SA, LPO, and PCC, along with increased transcriptional and enzymatic activities of TrxR2, SOD2, GPx1, and GR. Notably, the GSH/GSSG ratio was significantly reduced whereas NAD⁺/NADH and NADP⁺/NADPH ratios were significantly elevated. Metabolic exhaustion was also evident in senescent cells underscored by the severely diminished ATP/ADP ratio. Profound oxidative stress may contribute, at least in part, to senescence pointing at a potential protective role of antioxidants in aging-associated disease.

• 한국식품저장유통학회지
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• 제30권3호
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• pp.526-537
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• 2023

본 실험에서는 산마늘 추출물의 in vitro 항산화 및 in vitro 생리활성 효능평가를 진행하였다. 산마늘 추출물은 페놀성 화합물과 플라보노이드 화합물을 함유하고 있으며, ABTS, DPPH 라디칼 소거 활성 등을 나타내었다, 특히, 산마늘 추출물은 우수한 알코올 대사 관련 효소 활성을 나타내었으며 더불어, HepG2 세포에서 에탄올로 유도된 스트레스에 대해 세포 생존율을 유의적으로 증가시켰으며, 활성 산소종의 생성을 효과적으로 감소시켰다. 그리고 산마늘 물 및 60% 에탄올 추출물은 에탄올로 세포독성이 유도된 간세포에서 BCl-2, BAX 및 pro-caspase-3의 발현량을 개선함으로써 세포사멸을 억제하는 것으로 확인되었다.

• Toxicological Research
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• 제13권1_2호
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• pp.95-101
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• 1997

Ethyl carbamate (EC) is a potent teratogen in rodents and is present at low concentration in fermented foods and alcohol beverages. It has been well hypothesized that some metabolic products are responsible for the teratogenic effects of the compound. In the present study, the effects of phenobarbital (PB) on EC-induced embryotoxicity were investigated in SD rats. Six groups were constructed: EC 300 (EC 300 mg/kg/day), EC 600 (EC 600 mg/kg/day), EC 600+PB (EC 600 mg/kg/day and PB 80 mg/kg/day), PB (PB 80 mg/kg/day), DR (dietary restriction, 8 g/day/rat) and a control group. Rats of the EC 600+PB group were pretreated with phenobarbital intraperitoneally for three days to induce cytochrome P450 enzymes, followed by oral administration of EC for two consecutive days. The incidence of fetal deaths in the EC 600+PB group was higher than that of the EC 600 group(42.7 vs. 14.3%). The incidence of fetal realformations in the EC 600+PB group was higher than that of the EC 600 group (external; 7.0 vs. 4.1%, visceral; 31.4 vs. 11.3%, skeletal; 11.1 vs. 6.5%). There was no embryotoxicity in the control, EC 300, PB and DR groups. These results show that the pretreatment with phenobarbital augments EC-induced embryotoxicity in rats, indicating an evidence that metabolic activation by cytochrome P450 may be the major pathway of EC to its embryotoxic forms.

• Asian-Australasian Journal of Animal Sciences
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• 제24권1호
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• pp.110-124
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• 2011

Anatomically separate fat depots differ in size, function, and contribution to pathological states such as the metabolic syndrome. We isolated pre-adipocytes from different adipose depots, omental, subcutaneous and intramuscular, of beef cattle, and cultured in vitro to determine the basis for the variations and attribute these variations to the inherent properties of adipocyte progenitors. The proliferating cells from all depots before the confluence were harvested and the proteome was analyzed by a functional proteomic approach, involving 2-DE and MALDI-TOF/TOF. More than 252 protein spots were identified, selected and analyzed by Image Master (ver 7.0) and MALDI-TOF/TOF. Further, our analysis showed that there were specific differences in proteome expression patterns among proliferating precursor cells from the three depots. Sixteen proteins were found to be differentially expressed and these were identified as proteins involved in cellular processes, heat shock/chaperones, redox proteins, cytoskeletal proteins and metabolic enzymes. The results also enabled us to understand the basic roles of these proteins in different inherent properties exhibited by adipose tissue depots.

• Biomolecules & Therapeutics
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• 제22권2호
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• pp.149-154
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• 2014

Effects of diallyl sulfide (DAS) on thioacetamide-induced hepatotoxicity and immunotoxicity were investigated. When male Sprague-Dawley rats were treated orally with 100, 200 and 400 mg/kg of DAS in corn oil for three consecutive days, the activity of cytochrome P450 (CYP) 2E1-selective p-nitrophenol hydroxylase was dose-dependently suppressed. In addition, the activities of CYP 2B-selective benzyloxyresorufin O-debenzylase and pentoxyresorufin O-depentylase were significantly induced by the treatment with DAS. Western immunoblotting analyses also indicated the suppression of CYP 2E1 protein and/or the induction of CYP 2B protein by DAS. To investigate a possible role of metabolic activation by CYP enzymes in thioacetamide-induced hepatotoxicity, rats were pre-treated with 400 mg/kg of DAS for 3 days, followed by a single intraperitoneal treatment with 100 and 200 mg/kg of thioacetamide in saline for 24 hr. The activities of serum alanine aminotransferase and aspartate aminotransferase significantly elevated by thioacetamide were protected in DAS-pretreated animals. Likewise, the suppressed antibody response to sheep erythrocytes by thioacetamide was protected by DAS pretreatment in female BALB/c mice. Taken together, our present results indicated that thioacetamide might be activated to its toxic metabolite(s) by CYP 2E1, not by CYP 2B, in rats and mice.

• Parasites, Hosts and Diseases
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• 제55권2호
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• pp.121-128
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• 2017

Protozoan viruses may influence the function and pathogenicity of the protozoa. Trichomonas vaginalis is a parasitic protozoan that could contain a double stranded RNA (dsRNA) virus, T. vaginalis virus (TVV). However, there are few reports on the properties of the virus. To further determine variations in protein expression of T. vaginalis, we detected 2 strains of T. vaginalis; the virus-infected ($V^+$) and uninfected ($V^-$) isolates to examine differentially expressed proteins upon TVV infection. Using a stable isotope N-terminal labeling strategy (iTRAQ) on soluble fractions to analyze proteomes, we identified 293 proteins, of which 50 were altered in $V^+$ compared with $V^-$ isolates. The results showed that the expression of 29 proteins was increased, and 21 proteins decreased in $V^+$ isolates. These differentially expressed proteins can be classified into 4 categories: ribosomal proteins, metabolic enzymes, heat shock proteins, and putative uncharacterized proteins. Quantitative PCR was used to detect 4 metabolic processes proteins: glycogen phosphorylase, malate dehydrogenase, triosephosphate isomerase, and glucose-6-phosphate isomerase, which were differentially expressed in $V^+$ and $V^-$ isolates. Our findings suggest that mRNA levels of these genes were consistent with protein expression levels. This study was the first which analyzed protein expression variations upon TVV infection. These observations will provide a basis for future studies concerning the possible roles of these proteins in host-parasite interactions.

• Journal of Microbiology and Biotechnology
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• 제21권12호
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• pp.1211-1227
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• 2011

C57BL/6J mice have been widely used as a diet-induced obesity model because they trigger common features of the human metabolic syndrome. In the present study, C57BL/6J male mice were fed either a high-fat diet (HFD) or normal diet (ND) during a 24-week period, and then the age-dependent liver proteome of mice in two groups was analyzed using 2-DE combined with MALDI-TOF-MS. Among identified proteins, up-regulated proteins were subdivided to early (during the first 4 weeks) and late (20~24 weeks) markers that played a role in diet-induced obesity development. Important early markers included ketohexokinase and prohibitin, and late markers included the 75 kDa glucose-regulated protein, citrate synthase, and selenium-binding liver protein. Of these, the 75 kDa glucosere-gulated protein has already been linked to obesity; however, prohibitin protein involved in obesity was identified for the first time in this study. In order to validate the proteomic results and gain insight into metabolic changes between the two groups, we further confirmed the expression pattern of some proteins of interest by Western blot analysis. Combined results of proteomic analysis with Western blot analysis revealed that antioxidant enzymes were progressively decreased, whereas cytoskeletal proteins were time-dependently increased in HFD mice.

• 생명과학회지
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• 제25권12호
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• pp.1450-1457
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• 2015

화석 연료의 고갈과 환경 문제를 극복하기 위하여 식물성 바이오매스를 이용한 바이오연료의 생산이 큰 주목을 받고 있는 가운데 화학적 전처리를 하지 않은 바이오매스를 직접 분해할 수 있는 그램 양성 초호열성 세균 Caldicellulosiruptor bescii에 대한 관심이 높아지고 있다. C. bescii는 식물 세포벽을 구성하는 셀룰로스, 헤미셀룰로스 등의 분해 뿐만 아니라 세포벽을 연결시켜주는 pectin도 효율적으로 분해할 수 있는데 최근 C. bescii의 genetic tool이 개발되면서 바이오매스 분해에 관여하는 효소의 특성 규명과 아울러 대사공학적 방법으로 바이오에탄올을 생산하는 통합바이오공정(consolidated bioprocessing; CBP)의 개발이 가능케 되었다. 본 총설에서는 초고온성 세균인 C. bescii를 이용한 식물성 바이오매스의 분해와 바이오에탄올의 생산에 대한 최신 연구결과를 소개하고 향후 전망에 대해 논하고자 한다.